Powdering machine



Dec. 9, 1930., s. LIPSIUS 1,784,459

POWDERING MACHINE Filed Sept. 19, 1928 S Sheets-Sheet l INVENTOR RNEY Dec. 9, 1930. '5, ps us 1,784,459

-POWDERING MACHINE Filed Sept. l9. 1928 3 Sheets-Sheet 2 1930. s. LIPSIUS POWDERING MACHINE Filed Sept. 19. 1928 5 Sheets-Sheet 3 will...

INVENTOR Patented Dec.. 9, 1930 UNITED STATES SAMUEL LIPSI IIUS, OF NEW YORK, N. Y.

POWDEBING MAOHIN E Application filed September 19, 1928. Serial No. 806,850.

My invention relates particularly to machines forapplying powder to freshly printed sheetsfor the ultimate production of what is commonly termed raised or embossed printing. Some of the powder used in this work is very fine and of such a character that it is very difficult to handle. It is affected by moisture, by heat, and electrically. It will also be understood that for commercial production the process of application must be to a high degree automatic and reliable. Furthermore, the powder is quite expensive and-the process must therefore be economical with respect to the con- ,sumption' of the raw material.

It is the object of my invention therefore to provide a simple reliable mechanism for applying such powder to sheets of paper, cards, or the like, automatically and removing any excess of powder without waste.

Another object is to provide a construction ofthis character which will require a minimum application of powder for its operation.

Another object is to provide a construction of this character which is substantially fool proof and can be used for powdering either small cards or any size of sheet up to the maximum capacity of the machine. In carrying out my invention I employ a travelling conveyor belt for the cards or sheets which conveyor'is formed of canvas orother suitable material and preferably coveredwith rubber so that it is substantially impervious The upper run of this conveyor is preferably supported upon a stationary platform or table and the powder is automatically sifted or deposited from" a hopper located above the conveyor.

Immediately after thepowder has been deposited the conveyor and the sheets upon it are subjected over a limited area to rapid vibrations tending to loosen and raise any particles of powder which have not adhered to the tacky ink on the sheets. Immediate- 1y above the conveyor and adjacent the vibrator is located a suction inlet for instantly picking up these loosened particles of powder and conveying them back to the hoppet from which the powder is to be deposited.

Means is provided for keeping the conveyor smooth and guiding it straight so that the sheets upon it will lie flat, and the conveyor will stay on the rollers. Immediately following the conveyor and mechanism above described I'prefer to provide another conveyor or belt formed of wire mesh onto which the powdered sheets are deposited as they leave the canvas conveyor. The sheets on this foraminous conveyor may also be sub jected to vibration for the removal of any powder which may still adhere to the bottom of the sheet or to the top of the sheet. Such a, mesh-work conveyor is very desir-, able when the stock which is being handled is at all afiected by static electricity which causes the powder to adhere tenaciously and the metallic conveyor serves to assist in the release of the charge from the sheets and consequently more ready removal of the powder. This mesh-work also permits any powder which may have been transferred to the bottom of the sheets from the canvas conveyor to fall through. Both conveyors are preferably enclosed in a housing which may have suction means, to prevent escape of floating particles of-the powder and a receptacle is preferably provided beneath the conveyors to receive such particlesof powder as are not carried away on the sheets or picked up by the suction.

Fig. 1 is a side View of one form of construction embodying my invention.

Fig. 2 is a plan view of the same.

Fig. 3 is an enlarged sectional view show- 5 ing the preferred mechanism for applying the powder and the dislodging and suction devices for removing excess powder.

Fig. 4 is a side ,view and partial section more or less diagrammatic showing the conveyors andassociated mechanism.

Fig. 5 is a plan view of the same.

The conveyor belt 10 is preferably of canvas or similar construction and travels on rollers or pulleys 11 and 12. These are preferably provided with helically arranged projections .or threads 13, which tend to spread the belt from the center outwardly in opposite directions and keep it taut.

A take-up roller 14 may also be employed to keep the belt tight longitudinally on its upper surface. The upper surface of this belt travels on a table 15 and the powder is delivered to it in a substantially continuous very thin stream from a hopper 16 provided with a vibrating discharge control 17 in accordance with my previous Patent No. 1,696,171 dated Dec. 18, 1928. At a point a short distance beyond that at which the powder is deposited, a vibrator 18 is mounted beneath the conveyor which subjects the conveyor at this point and the sheet upon it to rapid vibration tending to raise from the sheet and conveyor any particles of the owder which have not already become attac ed to or eementedto the tacky ink on the sheet. Immediately above this vibrator 18 is located a suction head 19, connected to a fan 20 driven by motor 21. This fan lifts the particles of powder and forces the air with the powder into a circulating separator or chamber 22 of any suitable character which in turn discharges into the upper end of the hopper 16.

This hopper preferably has a distributing member 23 which has screw threads extending in opposite directions from its center so thatany excess of powder which collects in the center of the hopper 16 will be moved toward the opposite ends or sides of the hopper.

The outlet of air pressure from the separator may be provided with a bag 241 at its lower end for the escape of the air and the collection of powder.

Just beyond the conveyor 10 is located another conveyor 25 preferably of wire mesh. Beneath the run of this conveyor is the vibrator 26 tending'to shake off from the conveyor and from the sheets upon it any undersirable particles of powder. I

Loose rollers such as 27 and 28 may be provided for holding down the conveyor near the point where the conveyor and sheets are vibrated so as to control the vibration of the conveyor and prevent the sheets from rising. Guide wires 29 may also be provided beneath the suction head 19 to prevent small cards or sheets being turned over or drawn up into the suction pipe. p

A receptacle 30 is located beneath the conveyors to collect any particles of powder which may fall therein. A cup 31 may be provided at the lower end for collecting this powder so that it may be used again. A hood 32 is preferably arranged over the upper part of the conveyors to prevent the cscape of powder into the air of the room. This careful collection of the powder is not only for the protection of the workmen but also to save the expensive powder.

It will be understood that I preferably make the belt 10 somewhat wider than the discharge orifice from the hopper 16 so that all of the powder will fall well within the mouth of the conveyor and not fall off the edges. By having the belt about one-half inch wider on each side than the hopper outlet, the suction is able to ick up the excess powder before it can be vibrated off the edges of the belt. I also make the inlet or suction head 19 somewhat wider than the belt 10 so as to be sure and pick up the'loosepowder from the sheets and the conveyor.

The lower runs of the conveyors may be vibrated in the same manner as the upper runs to remove any powder which may still adhere and allow it to drop into the recep-- dered sheets may be fed automatically from the chute 34 to an oven or baking machine of suitable character (not shown).

In operation a sheet with freshly printed surface exposed, is placed on the canvas conveyor, either by hand or delivered from a printing press direct as shown in my former patents, which carries it under the powder depositing hopper, where powder is applied in a thin stream. The sheet then passes over the vibrating member and under the suction hood, where excess powder not adhering to the printed surface is removed.

The sheet then passes over the wire mesh conveyor and its vibrating member, where any particles that have not been cleaned off by the suction hood. are removed. All powder removed from the sheets and from the conveyor is sucked up by the suction hood, and blown into the cyclone separator, and then delivered to the powder distributing hopper for use over again.

The sheetafter leaving the wire conveyor enters the usual heating chamber (not shown) to fuse the powder, thus producing raised printing.

While it is understood that the excess powder may be sucked off the sheets without vlbration to aid, it is highly desirable to employ the use of vibration, so that comparatively very little suction be necessary to aceomphsh the result. It has been found that the use of strong suction, brings the sheets n1 forceful contact with the mouth of the suction hood and causing too much powder to be sucked off that should remain on the wet ink to be fused thereon, resulting in poor work. Again stron suction that would not necessitate the use 0 vibrating means, would requlre the use of larger air separating means, because of the greater volume of air to be separated from th powder. This would be objectionable because of the greater bulk and expense. If the separator was not made larger; the force of air would carry a great deal of powder through the outlet for air, and also air would be forced through the outlet for the powder. By employing vibrating means, as an aid to the suction means only about one quarter of the air is necessary to accomplish the same result and cleaning is better, especially where engraving effect powder is-used. This material contains granules, nothing larger than can pass a number 160 wire mesh, and has a tendency to stick to stock most tenaciously and is very difficult to handle.

The use of the wire conveyor following the canvas has been found very advantageous, especially in cases where stock is charged with static, which occurs quite often, and while for ordinary printing static is not a very great handicap, it is especially so in producing raised printing, (especially engravede-lfects) because of the difliculty of cleaning of the fine dust which if fused on the stock (not inked) feels rough and sandy. The wire conveyor has a tendency to help carry ofi the static from the charged sheets, and the vibrator loosens the powder both top and bottom, and allows the powder to fall into the receptacle. Some times the wire conveyor alone is sufficient to eliminate the excess static, without the aid of the additional vibrator.

I claim:

1. A powdering machine comprising a canvas conveyor, means for depositing powder on sheets on the conveyor, means for vibrating said conveyor to raise uncemented powder, a suction pipe having its inlet immediately above the canvas over said vibrating means and shaped for removal of substantially all the loose powder on said conveyor, and a grating between said conveyor and suction pipe inlet.

2. A powdering machine comprisinga canvas conveyor, means for depositing powder on sheets on the conveyor, means for vibrating said conveyor to raise uncemented powder and asuction pipe having its inlet immediately above the canvas over said vibrating means, and means disposed between the powdering means and suction pipe for. limiting the vibrated area of the canvas.

A powdering machine comprising a canvas conveyor, means for depositing powder on sheets on the conveyor, means for vibrating said conveyor to raise uncementedpowder and a suction pipe having its inlet immediately above the canvas over said vibrating means, and a wire mesh conveyor arranged in line with the canvas conveyor,

means for vibrating the mesh conveyor, and

a hood-enclosing a substantial portion of both conveyors.

4. A powdering machine comprising a canvas conveyor, means for depositing powder on sheets on the conveyor,'means for vibrating said conveyor to raise uncemented powder and a suction pipe having its inlet immediately above the conveyor over said vibrating means, means for limiting the vibrated area of the conveyor, a suction hood over said conveyor, suction pipe and deposit-- ing means, and a receptacle beneath said con veyor.

5. A powdering machine comprising an impervious conveyor, means ,for depositing powder on sheets on the conveyor, a table beneath said powdering means for supporting the upper run of the conveyor, means forvibrating said conveyor to raise uncemented powder and a suction pipe having its inlet immediately above the conveyor near an edge of said table and near said vibrating means, and a wire mesh conveyor arranged in line with the first conveyor, means for vibrating the mesh conveyor, and a powder receptacle beneath both vibrating means.

6. A machine for applying powder to small sheets and the like comprising a canvas conveyor, means for depositing powder on sheets on the conveyor, means for vibrating a lim ited area of said conveyor, a suction pipe having'its inlet immediately above the vibrating means, and members located beneath said inlet for guarding and guiding the movement of said sheets. i

7. A machine for applying powder to sheets comprising a conveyor having a substantially inpervious surface, means for depositing powder on sheets on the conveyor, means for vibrating a limited area of said conveyor, a suction pipe having an inlet immediately above and close to said vibrating means,-a metallic mesh-work conveyor receiving the sheets from the first conveyor, and a powder receptacle beneath the meshwork conveyor.

8. A machine for applying powder to sheetscomprising a canvas conveyor, means for depositing powder on sheets on the con- Veyor, means for vibrating a limited area of said conveyor, a table supporting said conveyor beneath said powdering means, loosely mounted rollers located above said conveyor adjacentsaid vibrating means, a suction pipe having an inlet adjacent said vibrating means, a metal mesh-work conveyor receiving the sheets from the first conveyor, 'and means for removing excess powder from the vicinity of the mesh-work conveyor.

9. A machine for applying powder to sheets comprising a non-metallic inpervious conveyor for the sheets, means for depositing powder on the sheets on' theconveyor, a table beneath said powdering means for support- 1ng part of the upper run of the conveyor, means for vibrating. a. limited area of the conveyor, a suction pipe having an inlet located adjacent the vibrating means, a metal- 1ic-mesh-vvork conveyor arranged to receive sheets from the first conveyor, a receptacle for powder beneath both of said conveyors, and a suction hood arranged over both of said conveyors.

SAMUEL LIPSIUS. 

